Updates any messages which were last edited by "MediaWiki default" to their current version. Creates any messages which did not exist.

rebuildMessages.php --rebuild

Updates all messages to their current default value, regardless of whether they have been manually edited. This is sometimes used on other wikis when a new messages file has just been created, with a comprehensive set of default messages. It has never been used on the English Wikipedia.

If the MediaWiki default account name does not exist, edits made by this script have a user ID of zero so they are treated as anonymous edits in the page history, with a link to the user contributions instead of the user page.

The same username is also used by the MediaWiki installer. Installing MediaWiki has the same effect as rebuildMessages.php --update.